Is lactulose contraindicated in pregnancy?

From the Guidelines

Lactulose is not contraindicated in pregnancy.

Treatment of Constipation in Pregnancy

• Constipation in pregnant persons can be treated with lactulose, a type of osmotic laxative, as well as dietary fiber and polyethylene glycol–based laxatives 1.
• The use of lactulose in pregnancy is considered safe, although it may cause maternal bloating 1.
• Best practice advice recommends the use of lactulose, along with other treatment options, for the management of constipation in pregnant persons 1.
• It is essential to note that stimulant laxatives should be avoided in pregnancy due to conflicting safety data, whereas bulk-forming agents like psyllium husk or methylcellulose are safe to administer 1.
• Pregnant women should be encouraged to maintain a high dietary fiber intake, consume adequate amounts of fluids, and avoid straining during bowel movements to prevent constipation and promote regular bowel movements 1.

From the FDA Drug Label

Pregnancy Teratogenic Effects Pregnancy category B. Reproduction studies have been performed in mice, rats, and rabbits at doses up to 2 or 4 times the usual human oral dose and have revealed no evidence of impaired fertility or harm to the fetus due to lactulose. There are, however, no adequate and well-controlled studies in pregnant women Because animal reproduction studies are not always predictive of human response, this drug should be used during pregnancy only if clearly needed.

Lactulose is not contraindicated in pregnancy, but it should be used only if clearly needed 2.

From the Research

Lactulose Use in Pregnancy

• Lactulose is not contraindicated in pregnancy, as it is not absorbed in the small intestine and does not appear to pose a threat to the fetus 3.
• Studies have shown that lactulose is effective in treating constipation in pregnant women, with significant increases in frequency of defecation and normalization of stool consistency 3, 4.
• Lactulose has been compared to other treatments, such as polyethylene glycol, and has been found to be safe and effective, although polyethylene glycol may have a faster therapeutic effect 4.
• Combination therapies, such as lactulose with glucomannan, have also been studied and found to be effective in controlling constipation and weight gain in pregnant women 5.
• Animal studies have also shown that lactulose supplementation can have beneficial effects on the gut microenvironment and pregnancy performance in mice 6.

Safety and Efficacy

• The US Food and Drug Administration (FDA) risk categories for lactulose are often based on a lack of studies rather than evidence-based information, and alternative solutions, such as those proposed by the American College of Gastroenterology's Committee on FDA related matters, (ACG-FDA) and the Motherisk Programme, can help improve decision-making 7.
• Lactulose has been found to be safe and well-tolerated in pregnant women, with no significant differences in adverse effects compared to other treatments 3, 4.
• The use of lactulose in pregnancy is supported by several studies, which have found it to be effective and safe for treating constipation in pregnant women 7, 3, 4, 5.